A simple, rapid and sensitive RP-HPLC-UV method for the simultaneous determination of sorafenib & paclitaxel in plasma and pharmaceutical dosage forms: Application to pharmacokinetic study

• A simple, economical, fast, and sensitive RP-HPLC-UV method has been developed for the simultaneous quantification of Sorafenib and Paclitaxel in biological samples and formulations using piroxicam as an internal standard.
• First method which simultaneously determines the Sorafenib and Paclitaxel in nano-pharmaceutical formulations and plasma with simple mobile phase composition and shorter analysis time.
• The method was successfully applied for the in-vitro studies of Sorafenib and Paclitaxel nanosuspension formulations and pharmacokinetics studies in animal models.

A simple, economical, fast, and sensitive RP-HPLC-UV method has been developed for the simultaneous quantification of Sorafenib and paclitaxel in biological samples and formulations using piroxicam as an internal standard. The experimental conditions were optimized and method was validated according to the standard guidelines. The separation of both the analytes and internal standard was achieved on Discovery HS C18 column (250 mm × 4.6 mm, 5 μm) using Acetonitrile and TFA (0.025%) in the ratio of (65:35 V/V) as the mobile phase in isocratic mode at a flow rate of 1 ml/min, with a wavelength of 245 nm and at a column oven temperature of 25 °Cin a short run time of 12 min. The limits of detection (LLOD) were 5 and 10 ng/ml while the limits of quantification (LLOQ) were 10 and 15 ng/ml for sorafenib and paclitaxel, respectively. Sorafenib, paclitaxel and piroxicam (IS) were extracted from biological samples by applying acetonitrile as a precipitating and extraction solvent. The method is linear in the range of 15–20,000 ng/ml for paclitaxel and 10–5000 ng/ml for sorafenib, respectively. The method is sensitive and reliable by considering both of its intra-day and inter-day co-efficient of variance. The method was successfully applied for the quantification of the above mentioned drugs in plasma. The developed method will be applied towards sorafenib and paclitaxel pharmacokinetics studies in animal models.